The Efficacy of Combined Melatonin and Methylphenidate in Attenuating Pyroptosis and Cognitive Deficits Induced by Aluminum Chloride Administration in BALB/C Mice

Abstract

Background: Aluminum chloride (AlCl3) exposure is implicated in Alzheimer's disease (AD) pathogenesis, inducing cognitive deficits, oxidative stress, and neuroinflammation. Pyroptosis, an inflammatory form of cell death driven by the NLRP3 inflammasome, is a critical link between these pathologies. Objectives: This study investigated the combined efficacy of melatonin (MEL), an antioxidant and anti-inflammatory agent, and methylphenidate (MPH), a cognitive enhancer, against AlCl3-induced neurotoxicity. Methods: Male BALB/c mice were divided into six groups (n = 6): Control, sham (MEL 10 mg/kg + MPH 10 mg/kg), AlCl3 (300 mg/kg), and AlCl3-treated groups with MEL, MPH, or their combination. After 15 days of treatment, cognitive function was assessed via a passive avoidance test. Hippocampal tissues were analyzed for oxidative stress markers [reactive oxygen species (ROS) and myeloperoxidase (MPO)] and key pyroptosis proteins [NLRP3, cleaved caspase-1, gasdermin D (GSDMD)] using biochemical assays. Results: The AlCl3 administration significantly induced cognitive impairment in the passive avoidance test, increased ROS production and MPO activity, and upregulated hippocampal levels of NLRP3, cleaved caspase-1, and GSDMD. While MEL and MPH monotherapies showed modest benefits, their combination produced the most robust effects. The combined treatment significantly reduced oxidative stress markers and markedly suppressed the expression of all measured pyroptosis-related proteins compared to the AlCl3 group. Conclusions: The combination of MEL and MPH demonstrates a superior protective effect against AlCl3-induced neurotoxicity compared to either drug alone. The therapeutic mechanism appears to involve the synergistic inhibition of the NLRP3/caspase-1/GSDMD pyroptosis pathway and the mitigation of MPO-mediated oxidative stress, presenting a novel combinatorial strategy for alleviating neuroinflammation in AD-like pathology.